I'm affected with the same typical setup (Ubuntu, amd64, installed with existing partitions for / (with formatting) and /home (without formatting). For me, the workaround described in #924660 worked (install without /home and manually add it to the fstab after installation).
I guess this is a duplicate of #924660.
I'm affected with the same typical setup (Ubuntu, amd64, installed with existing partitions for / (with formatting) and /home (without formatting). For me, the workaround described in #924660 worked (install without /home and manually add it to the fstab after installation).